Fix device detection to properly parse lsblk output

- Handle lsblk tree symbols (├─, └─) in device parsing
- Extract base device names from partitions (nvme0n1p2 -> nvme0n1)
- Support both NVMe and traditional device naming schemes
- Fixes missing device lines in storage display

agent/src/collectors/disk.rs

@@ -277,14 +277,54 @@ impl DiskCollector {
         for line in output_str.lines() {
             let parts: Vec<&str> = line.split_whitespace().collect();
             if parts.len() >= 2 && parts[1] == mount_point {
-                let device_name = parts[0].trim();
+                // Remove tree symbols and extract device name (e.g., "├─nvme0n1p2" -> "nvme0n1p2")
-                return Ok(vec![device_name.to_string()]);
+                let device_name = parts[0]
+                    .trim_start_matches('├')
+                    .trim_start_matches('└')
+                    .trim_start_matches('─')
+                    .trim();
+                
+                // Extract base device name (e.g., "nvme0n1p2" -> "nvme0n1")
+                if let Some(base_device) = Self::extract_base_device(device_name) {
+                    return Ok(vec![base_device]);
+                }
             }
         }
         
         Ok(Vec::new())
     }
 
+    /// Extract base device name from partition (e.g., "nvme0n1p2" -> "nvme0n1", "sda1" -> "sda")
+    fn extract_base_device(device_name: &str) -> Option<String> {
+        // Handle NVMe devices (nvme0n1p1 -> nvme0n1)
+        if device_name.starts_with("nvme") {
+            if let Some(p_pos) = device_name.find('p') {
+                return Some(device_name[..p_pos].to_string());
+            }
+        }
+        
+        // Handle traditional devices (sda1 -> sda)
+        if device_name.len() > 1 {
+            let chars: Vec<char> = device_name.chars().collect();
+            let mut end_idx = chars.len();
+            
+            // Find where the device name ends and partition number begins
+            for (i, &c) in chars.iter().enumerate().rev() {
+                if !c.is_ascii_digit() {
+                    end_idx = i + 1;
+                    break;
+                }
+            }
+            
+            if end_idx > 0 && end_idx < chars.len() {
+                return Some(chars[..end_idx].iter().collect());
+            }
+        }
+        
+        // If no partition detected, return as-is
+        Some(device_name.to_string())
+    }
+
     /// Get directory size using du command (efficient for single directory)
     fn get_directory_size(&self, path: &str) -> Result<u64> {
         let output = Command::new("du")